Until few months back I had only one FTTH broadband connection and a single WiFi router serving my home. Now I added a second FTTH broadband connection (from a different ISP) and added a second WiFi router.
The two WiFi routers (router#1 and router#2) are placed about 2 feet away from each other, and both seem to work fine after a power-cycle but their performance seems to degrade over time (in 4-5 hours). Both routers are 2.4GHz, 300mbps basic SOHO routers. I could still make do with this arrangement to an extent, but coverage was bothering me.
So I bought a 3rd router (router#3) which is a AC1200 dual-band router. This new router (#3) is connected over wired LAN to router#1, and it is configured to operate in router-mode (not as an AP, WISP, range-extender mode).
The introduction of this router seems to be making things worse. I can barely ever connect to this new router and invariably always land up in a 'No internet' state. It seems I can connect to it, after my laptop/mobile have been in airline mode for few hours, and all the routers have just been restarted. After a while this stops working, and my laptop/mobile would invariably have fallen back to the older routers.
As for DNS settings here is what I have:
- On primary router (directly connected to FTTH converter): DNS --> Google public ones (126.96.36.199 / 188.8.131.52)
- On secondary router (AC1200, new one, pointing to primary router): DNS --> primary router IP, google public one (184.108.40.206)
Edited: Updated diagram to show both FTTH-ISP connections & all 3 WLAN-routers. The problem seems to be compounded somehow by the relationship between the primary router (router#1) directly connected to FTTH converter, and the secondary router (new AC1200 one - router#3) which points to the primary as gateway.
Looking for some potential causes and suggestions on how to troubleshoot the issues with this new router.
One of my suspicions is some sort of MAC-address conflict. This could be because router#1 sees same device (MAC-id) twice once where device connects to it directly and then due to some transient issue, connects to router#3. Since router#3 then connects to router#1 as gateway, router#1 sees the same MAC-id again. Not sure how to confirm this as the issue or fix it.
It is unlikely to be channel conflict as I have tried explicitly setting to different radio channels (each router -- while scanning neighbourhood radio frequency signal strengths), but finally settled on keeping it auto. In auto channel selection, the router's radio module should select the least busy / least conflicting channel.
Edit: Found some interesting explanation here on cascading routers